Any use GL4 Synthetic in Toploader or T10 ??

[winr1]

Also, standard or synthetic weight of oil

75/90 .... 90/140 ... etc ..




Ricky.

[6667fan]

GL-4 conventional is the way to go. It is good for trans with yellow metals. Synthetic has an undesirable feature but I can’t recall what it is. Don’t fall for a GL-5 oil being good enough because it is newer and supercedes  GL-4.  Napa carries a GL-4 and there is the Driven line of products. 80/90 is fine and is probably what you will find.
JB

[machoneman]

Here's the deal. Do  not use syn oil in any 4-5-6 speed tranny that has brass synchro rings. Syn oil is too slippery to allow easy shifting (dog ring engagement).  Many modern trannys do recommend syn oil but it's becasue they use carbon fiber or otherwise non-brass syncho rings.

[BattlestarGalactic]

I run good ol "whatever" it is at Autozone.   Coastal brand?  Nothing fancy.  Std gear lube.  No fancy additives, NO synthetics.  75w90 is good.   The thicker 85w140 is tough to spin around in cooler weather.

I used to run the thick stuff way back.  You couldn't release the clutch in cold weather starting.  It would stall the engine LOL!!!  I had to ride the clutch to get the gears spinning over, then release and let the truck warm up.

[e philpott]

Just don't let them sell you GL5

[winr1]

Thanks guys :-)

I found a gallon of GL-4 85/90 Sta-Lube on Amazon, $13.99 and free shipping

Found 20 or so forums where as folks allowed they had used it for years




Ricky.